I've tried using some of the brushes that come with Illustrator but I can't seem to achieve those distressed borders (please click on the image to see what I'm talking about.). Not sure if it's a brush or an effect. Thanks.
It looks to me like the that the splatter pattern is only on the top and bottom (and extreme right side) of the graphic.
That effect might be easier to create and control with an grunge pattern overlay on top of a solid color pink line (that itself looks like a grunge brush) than with a complex brush.
That's definitely how I'd tackle it.